When setting up a device via the web tool, on the last page, if one attempts to re-use a name that's already associated with another device, it will result in an error message. Something like "Unable to name device. The problem happened at our end". (not an exact quote) That makes it sound like a server-side error and after a couple attempts it was tempting to give up and try again later assuming the server issue was intermittent.
A better error message would tell the user the cause and the fix, i.e. tell them the name was already in use and direct them to either use another name or go to the devices console page to rename the other device.
thanks.